Roseville using aquifer storage to retain excess water from storms
ROSEVILLE — With each storm, there's a similar question as area reservoirs release excess water: why are we getting rid of what we need?
Most local dams release water as a means of flood control with the expectation that more storms will come later in the year. But that still doesn't change the base of the question of how we hold onto all this excess water. A piece of that answer may be in Roseville.
"The future of California water is underneath our feet," said Ryan Ojakian who works in government affairs for the Regional Water Authority.
Every raindrop counts in California, and capturing those drops has become a new challenge as drought conditions have forced agencies to rethink how they handle the wetter months of the calendar.
"All the precipitation is going to come at once, and so the dynamic that we're seeing today of being in drought but having flood conditions, that is our future," Ojakian said.
In Roseville, Assistant Environment Utilities Director Sean Bigley walked CBS13 through how the city is retaining water.
"You're able to really bank water during these wet times so that in the future, if we are in drier drop periods, we can actually extract that water and use it for serving our customers," Bigley explains.
Roseville uses aquifer storage and recovery wells -- ASR for short -- in a project that is relatively unique regionally and statewide. The city has been working on this project since the early 2000s and got its first well online in 2006. Currently, there are five operating wells with two more slated to open this year.
To get the water and store it, the city receives an update and permission from Folsom Lake that they could store some of the water being released due to flood control. Roseville takes that water, puts it through its water treatment plant and then stores it in aquifers for later use. The aquifer capacity is 60 million gallons, or enough to provide water for 300 homes for an entire year. While that number doesn't seem like a lot, the project at scale could be a game-changer in the area.
"This technology is going to be increasingly important as we go into the future," Bigley explained.
While ARS wells aren't necessarily the silver bullet that can combat drought effectively, Ojakian said it's one of the many tools in the belt. Sacramento's groundwater basin is massive and Ojakian said that the current infrastructure can meet the needs of 180,000 homes in the region. But the existing infrastructure isn't fully utilized. If it were -- and if the projects the RWA has earmarked come to fruition -- up to 250,000 homes could be positively impacted by this saved water.
"The water bank has a capacity that's twice the size of Folsom reservoir, so about 2,000,000 acre-feet of storage," Ojakian explained.
A major component of recharging the groundwater basin is taking advantage when surface water areas are swelling.
"The surface water is so plentiful right now, if you take that from that source and you stop taking from the groundwater, you're going to fill up your groundwater basin," Ojakian said.
That's a simplified way of looking at it, Ojakian told CBS13, but is tje general concept. Over in Roseville, the city's 15-plus year project is finally starting to get some recognition as a potential way forward to keep the valley green, even deep into the summers, and lessen drought conditions.
"Our region has pretty bountiful surface water supplies but in some cases, we are dealing with those extremes," Bigley concluded. "So what we're able to do through this technology is actually take water that probably the majority of it would flow out to the Pacific Ocean and take at least a portion of that water and put it to good use."